The exemplary embodiments described herein relate to methods of forming proppant packs in subterranean formations.
Subterranean formations are often stimulated by hydraulic fracturing operations to enhance the volume of fluid produced from the formation in later production operations. In traditional hydraulic fracturing operations, a fracturing fluid, which may also function simultaneously or subsequently as a carrier fluid, is pumped into a portion of a subterranean formation at a rate and pressure sufficient to create or extend at least one fracture therein. Typically, particulate solids, often referred to as “proppant particles,” are suspended in a portion of the fracturing fluid or a subsequently introduced proppant slurry. The proppant particles fill at least a portion of the fractures to form a “proppant pack” and serve to prevent the fractures from fully closing once the hydraulic pressure is removed. By keeping the fractures from fully closing, conductive paths are formed through which fluids produced from the formation may flow.
The degree of success of a subsequent production operation depends, at least in part, upon the porosity and conductivity of the proppant pack. The porosity and conductivity of the proppant pack may reduce over time as some of the proppant particles eventually crush under the continuous closure pressure applied by the formation. Additionally, in proppant-free volumes of the proppant pack, the formation closure pressure (without resistance from proppant particles) may deform over time causing the cross-section of the fracture at the proppant-free volume to reduce and potentially close, sometimes referred to as “pinching off.” In some instances, the pinching off at proppant-free volumes of a fracture may be exacerbated by the foregoing loss of proppant particles in adjacent areas.